It's usual to get a reminder six weeks before your current fix is due to end.

If/when you fix again then the new fix will start from the date that you do it.

So if your current tarrif is less than the new one then you might want to wait a few weeks still at the lower price.
At the risk that the new tariff may change again before you do fix, (it could go either up or down).

There again if one of the new tariffs that you are offered is less than you pay now then you would probably want to change to it straight away.

If you don't fix again then when your current fix ends you will be automatically transferred onto the Standard Variable Tariff.

Thanks for the quick reply.  I will leave it a few weeks.  Either way, am I right that within the 49 days I will not be charged the Exit Charge?

Entirely your choice to fix again now or wait a few weeks.

Did your invitation give you examples of the new fixed tariffs that you are eligible for?
If not then you may want to check what you rates you could be getting:

PS. That’s correct,there’s no exit fee in those last 49 days of a fix, even if you change to a different supplier.
 

Hey @TerryBones 

Welcome to the OVO Online Community

If you renew new, your new plan will start from the date the current one ends. 

https://www.ovoenergy.com/help/article/contract-renewals

Found the plan for you? Click ‘Renew now’ to choose this plan. You’ll then receive a confirmation email of your new plan details and the new plan will begin the day after your current plan ends.

If you haven’t selected a new plan before your current plan comes to an end, your account will automatically roll onto our Simpler plan. This is a flexible variable tariff that is protected by the Variable Price Cap, read more about this here.